Studs for tires



Oct. 8, 1968 c. J, sMlTH 3,404,718

STUDS FOR TIRES Filed April 12, 1966 Z4 2;; Za a Uniwd tew Pate 7 STUDS EOR TIRES Clarence J. Smith-Rockford, Ill. ,.assignor toThe Shaler Company, Waupun, Wis. a corporation of. Delaware Filed Apr. 12, 1966, Ser.'No; 542,075

' Claims. (Cl. 152-210) ABSTRACTDF THE DISCLOSURE l .This invention relates to;a method for making anti-skid studs for vehicle tires and alsorelates to the studs made by such a method.

An important object of the invention ,is to utilize components with commercially available tolerances to obtain a tire stud part correctly dimensioned as to its overall.length. so that it properlyprojects from a tire after unt Another object of this invention iS a method for making tire studs in which problems of controlling dimensions in making such studs are substantially reduced.

Another object is a method in which atire stud is made byinserting a wear-resistant pin inan elongated socket without requiring critical control of the length and cross section of said socket.

,Anothenobject is a method for making tire studs in which a wearing pin insert may be.s electively positioned within a socket without fully inserting said pin therein,

' whereby said position is maintained for a subsequent step of securely fixing the wearing insert within the shell.

Another object is -a method for making tire studs wherein a shell with an enlarged head and an elongated shank containing a socket is joined to a'wearing pin insert in a fewcontrolled steps without critically controlling the leugthand diameter of the socket and the length of the insert in order to still obtain a completed tire stud with a high degree of dimensional accuracy relative to the overall length. 1 4

Another objectis the tire stud prepared by the method of the foregoing objects. in which a wearing pin extends out of a shell a preselected distance so that the length of the completed, stud conforms to a selected accuracy for 8111386? quent use ina given vehicle tire, p

Another objectis a..tire stud prepared by the method of the foregoing objects in. whicha wear-resistant pin is securely fixed by various means within a socket of a shell without requiring the pin to be bottomed in said socket.

Another objeet is a tire stud with a high degree of dimensional accuracy.

Another object is a tire stud that will tightly interlock in the tire and will not rotate.

Another object is a swaged tire stud.

-Another object is a method of securing together the shell and carbide insert of a tire stud to obtain a high degree of dimensional accuracy.

The foregoing objects are attained along with other objects which will become apparent from considering the following disclosure which includes drawings.

3 ,404,7 18 "Patented O ct ...8, 15268 FIGURE 1 is a side view of the stud with insert in place; i t g FIGURE 2 is a section taken on the-line 2 -2 of Figure FIGURE. 3 isa'-- bottom view. of .FIGURE'I} FIGURE 4 is a top view of FIGURE l-;'- and FIGURE 5 isa sequence of stepsin the method of as sembly The stud :is ilustra'ted .as: having an integrally formed body section or shell, shown generally at.10, in which is mounted a wear-resistant pin 12, for exampletungsten carbide, extending out of the shell a preselected distance. The shell 10 has an enlarged head 14 in the general shape of a. truncated cone. The head is shown with a central recess or well 15. The topside of the head has a plurality of smaller wells or pits 16. The wellsand pits contribute to a more secure anchoring of the stud when his positioned in place in a vehicle tire. Extending from the head is an elongated shank 18 which. is shown with a continuous .wall 20 shaped .so that theshank is formed as a cylinder. Inside the shank is a socket- 22 shown as being circular along a substantial portion of its axial length. The socket bottom 23 is shown as the tapered cone.

The shank is shown with two or more crimps or indents such as 24 and 26 which provide projections 24a and 26a in the bore of the shell. The projections approach each other or close the .bore sufliciently such that whenthe wear resistant material is inserted, an interference fit is created. Thus the wear resistant material can be'freely inserted until it hits the interference fit after which it must be pushed into the reduced area' until its position is desirably fixed. This-provides an interlock so that the insert will hold its position during'subsequent handling and permanent fix ing of theinsert within the shell, The interference means may be variously positioned along the shank to provide different initial frictional engagements to thereby better accommodate any desired changes in different-embodi ments.

Thecontinuous wall 20 of the shank is shown with a plurality of grooved deformations,"one of which is indicated at 30. Such grooved deformations are shown as'alternating with ribs, one of which is shown at 32. Alternating grooves and ribs represent, in the illustration, a plurality of swage deformations which have been-impressed in the continuous wall of the shank to securely fix-the pin 12 within the socket 22. The swage deformations can be impressed by moving the elongated shank with the' mounted pin through a swage die in which a plurality ofswaging elements are spaced so that the materialof theshank can flow between the swaging elements during the swaging formation. Such a cold metal flow in the illustra' ted. embodiment is represented by the ribs 32'. In practice,

. the shell is slightly elongated by such swaging, but suchelongation is easily controlled in order to still obtain a completed studof accurate dimensions in its overall length.

The method for making the tire studs can be illustrated by the sequence of steps shown in FIGURE 5. In step 1, the left view in FIGURE 5, a body section 36 is seenprovided witha substantially uniform diameter socket 38. This blank is formed without critical dimensioning of the socket within the body section. Such dimensioning would include the axial length of the socket, its diameter,

critically determined. The pin is inserted into the socket and moved into frictional engagement with the deformations, as indicated in step 3 of FIGURE 5. Appropriate forces are applied to the pin and it is moved further into the socket while maintaining interlocking engagement with the reduced portion or interference means within the socket. This movement is continued until the outer end of the pin extends out of the shell a preselected length at which time the inner end will still be short of the socket bottom. This results in the completed stud with desired accurate dimensioning of its length. This is indicated by step 4 in FIGURE 5. In this embodiment, the deformations 40a, 42a are further deformed by the advancing end of the pin as it is moved in frictional engagement through the reduced portion. After the pin is moved to the desired degree, the frictional engagement of the pin within the socket will cause the pin to retain its position until it is securely fixed within the shell. This step of securely fixing the pin is indicated in step 5 of FIGURE 5 wherein the plurality of swage deformations, indicated generally at 46, are impressed in the body section. Since the pin 44 is of a wear-resistant material much harder than the material of the body section, the pin can deform the interference means disposed within the socket upon application of force to the pin. In this embodiment, the pin may be said to be in deformable engagement with the interference means within the socket.

The use, operation and function of this invention are as follows:

The tire stud must have an accurate, overall length, and this is controlled by the preselected length of the pin or insert which extends out of the stud. The wear of the pin is related to the wear of the tire in such a way that the length of the pin extending out of the shell is desirably maintained relatively constant as both the pin and the tire undergo wear. Such pin material is, of course, more wear-resistant than the shell. For example, the pin may be of tungsten carbide while the body section may be made of low carbon steel. Other materials may be used, including non-carbide inserts such as ceramics or other wear resistant equivalents.

If the pin insert wears quickly relative to the tire, the anti-skid function of the studs will be prematurely lost through wear, and if it wears too slowly, the pin will extend too far out of the tire and lead to undesirable effects. This will include a loss of the desirable working relationship between the tire and pin contact surfaces as well as the possibility of aggravated road damage.

The method of this invention and the tire stud produced thereby permits a pin insert of a given wear-resistant material to be readily mounted with a preselected extension from the shell irrespective of the length of the socket in the shell or body section. It is possible to have available, for the practice of this method, standard shells made with sockets having commercially available tolerances in the length and diameter of the sockets. Also, standard inserts may be used with commercially available tolerances. By this method a stud with desirable, accurate dimensions of overall length can be formed from components having such commercial tolerances.

An interference will be formed within the socket of the shell by means such as crimping the continuous walls of the shank. Various equivalent interferences may be provided 'by other means which lead to a reduced portion in the socket to provide such interference. While the crimp is particularly illustrated, it will be recognized that other portions can replace crimping, such as providing a portion of the socket with a reduced diameter, forming the socket with an inwardly formed flange, providing ribs within the socket, or the like. In any event, a tire stud with such interference formed in the socket is combined with a pin insert of a given wear-resistant material by first inserting the pin in the socket until it frictionally engages the interference. A slight force will be necessary to move the pin into the intereference, and such frictional engagement will allow the wear-resistant pin to be inserted controllably until the preselected extension on the shank is attained. The in then can be securely fixed in the body section so that it can stand up under its expected use as a tire stud in operation.

The insert is preferably mechanically held in the shell by swaging which does not require any adhesives, soldering, brazing and the like, all of which involve an extra step and are more expensive for many embodiments. Whi e swaging is the preferred step for many embodiments, it is understood that other bonding and fixing means may be used and may even be desirable for certain embodiments using certain types of materials. Such other means may include brazing, soldering, resin adhesives and the like.

The swaging step, in addition to providing a tight interlock between the insert and shell, also results in a ribbed exterior along a portion of the shells exterior surface such that when the stud is forced into a bored or molded hole in a tire, the ribbed or fluted exterior surface will tightly interlock with the rubber. This will prevent the stud from tending to rotate or shift, thereby reducing frictional wear, abrasion of the rubber, excess heat generation, etc. The lands or top surfaces 32 of the ribs may be considered to be slightly larger in diameter than the original shell since the swaging action will probably cause the metal in the intermediate areas to flow outwardly somewhat. Thus, the diameter of the shell across the ribs may be somewhat greater than the diameter of the smooth portion of the shell directly next to the head 14.

It is the distance from the top of the enlarged head to the end of the insert, or the overall length of the stud, that is important. This determines how much the insert projects beyond the tire since the blind bores in the tire are of predetermined and known length. This dimension must be closely and accurately controlled to obtain most efficient use of the stud. Tolerances are extremely difficult to maintain in a product of this nature, particularly if the insert bottoms in the shell. By the present arrangement, it will be noted that the distance between the inner end of the insert and the bottom of the channel or socket in the shell is of no importance and, as a matter of fact, may vary somewhat from one stud to another. But what is important is that this space or gap exists. If the insert bottoms in the shell, the contact between the inner end of the insert and the bottom of the shell will control the amount that the insert projects out of the shell; therefore, the length of the stud. Since the overall length must be accurate, it is not possible to use components with commercially available tolerances. The tolerances must be critically controlled in such a prior art method. Since tire studs of this nature must be rapidly produced as a high volume item, exceedingly accurate tolerances in the dimensions of the components cannot be maintained. For example, the depth of the socket or channel in the shell will vary from time to time. So will the length of the insert.

But by the present method and structure, the insert can be made to project the same amount, and any commercial variation in tolerances or dimensions will be taken care of by the gap between the inner end of the insert and the bottom of the shell socket. The completed stud can still be accurately dimensioned as to its overall length.

A plurality of such tire studs are mounted in the surface contacting area of a vehicle tire according to known methods which may include simply providing a plurality of sockets in the tire surface and then forcing the stud into such sockets by appropriate means so that the enlarged head is securely fixed within the tire and the wearin g insert extends out of the tire.

The foregoing invention can now be practiced, and such practitioners will know that the invention is not necessarily restricted to the particular embodiments presented herein. The scope of the invention is to be defined by the terms of the following claims as given meaning by the preceding description.

I claim:

1. A tire stud including a body section having an elongated shank with an enlarged head at one end, a longitudinal bore in the shank, a pin of wear resistant material sized normally for clearance within the bore, one end of the pin extending out of the shank and terminating a predetermined distance from the free end of the shank, the other end of the pin in the bore terminating in a spaced but arbitrary relation to the other end of the bore, and means projecting inwardly in the bore to frictionally engage and hold the pin in the above recited relationship, a substantial portion of the exterior of the shank being swaged inwardly so as to grip and firmly hold the pin in the bore.

2. The structure of claim 1 further characterized in that the means projecting inwardly comprises two opposed crimps formed in the shank and sized to define an internal clearance therebetween which is less than the cross sectional dimension of the pin.

3. The structure of claim 1 further characterized in that the bore and pin are generally cylindrical.

- 4. The structure of claim 1 further characterized in that the swaged portion of the shank extends from the free end of the shank over more than half of the shanks total length.

5. The structure of claim 1 further characterized in that the bore is closed at the head end of the shank.

References Cited UNITED STATES PATENTS 3,230,997 1/1966 Carlstedt 152-210 FOREIGN PATENTS 1,202,156 9/ 1965 Germany.

ARTHUR L. LA POINT, Primal Examiner.

C. B. LYON, Assistant Examiner. 

